SAN FRANCISCO (Reuters) - California oil drilling regulators on Tuesday ordered operators of 12 underground injection wells in Kern County to halt injections out of fear that they could contaminate drinking water supplies.
The action is part of a statewide review of California’s 50,000 underground injection wells, which oil companies use to dispose of billions of barrels of undrinkable water produced every year during oil production.
The review began last summer after it was discovered that some injection was taking place into zones not approved by the U.S. Environmental Protection Agency under the terms of the Safe Drinking Water Act.
“As we’ve said before, the protection of California’s groundwater resources – as well as public health - is paramount, particularly in this time of extreme drought,” said Steven Bohlen, state oil and gas supervisor.
He said that limited testing of water supply wells by the Water Board has so far revealed no contamination of water used for drinking or agriculture.
The 12 wells ordered to halt injections include three operated by Linn Operating, Inc three operated by California Resources Corp (formerly Vintage), two each operated by E&B Natural Resources Management and Chevron U.S.A., and one each operated by Modus Inc and Western States International Inc.
Last summer, 11 Kern County wells were ordered to stop injections for fear of water contamination.
The oil operators of the 12 wells will be required to sample the groundwater at the point of injection for testing, regulators said.
Environmentalists said Tuesday’s order did not go far enough, noting that a report by the California EPA said the state Water Board has identified more than 200 injection wells of highest concern for potential risk to water supplies.
“Shutting down 12 illegal injection wells barely scrapes the surface of this threat to our drinking water,” said Kassie Siegel, an attorney with the Center for Biological Diversity. “Before this gets any worse, we need Governor Jerry Brown to order an immediate halt to all illegal oil wells in protected aquifers,”
Because of the nature of California’s geology, drilling for oil and gas yields far more water than oil. In 2014, California produced 205.3 million barrels of oil, but more than 3.3 billion barrels of water, which is usually brackish and unsuitable for human use. That water is typically disposed of by being injected back into the reservoir from which it was produced.
Reporting by Rory Carroll